Treatment of Synchronous Mucinous Carcinoma and Endocrine Mucin–Producing Sweat Gland Carcinoma with Mohs'' Micrographic Surgery

BACKGROUND: Endocrine mucin-producing sweat gland carcinoma is a very rare cutaneous tumor that has been reported only in three patients previously. We report a case of an endocrine mucin-producing sweat gland carcinoma associated with mucinous carcinoma treated by Mohs' micrographic surgery. OBJECTIVE: The purpose of this report is to test the utility of Mohs' micrographic surgery in the treatment of mucinous carcinomata. METHODS: A 79-year-old female with a 2-year history of four lesions of biopsy-proven endocrine mucin-producing sweat gland carcinomas and mucinous carcinoma was treated with Mohs' micrographic surgery. RESULTS: Three of the lesions were completely cleared by Mohs' micrographic surgery. The fourth lesion, in the right lateral canthus, was not cleared by the Mohs' technique because of its location within the orbit and the difficulty of retraction of the globe for appropriate visualization and excision. The patient underwent wide excision of the remaining orbital tumor and reconstruction, which was successfully accomplished. The patient did not experience a recurrence in any of her four lesions over a 2-year follow-up period. CONCLUSION: Mohs' micrographic surgery is an appropriate treatment for mucinous carcinomata, including endocrine mucin-producing sweat gland carcinoma and mucinous carcinoma.     

Basal Cell Carcinoma Arising in a Port-Wine Stain

BACKGROUND: The occurrence of basal cell carcinoma within a port-wine stain or nevus flammeus is rare. Sixteen cases of basal cell carcinoma which developed in a port-wine stain or nevus flammeus have been reported. OBJECTIVE: The objective was to demonstrate a rare case of basal cell carcinoma occurring in a port-wine stain successfully treated with Mohs micrographic surgery. METHODS: This is a case report and literature review. RESULTS: An 87-year-old man presented with a basal cell carcinoma on the margin of a previously untreated port-wine stain on the left cheek. Histologic examination showed a nodular basal cell carcinoma. The basal cell carcinoma was completely excised with Mohs micrographic surgery and complex linear closure was used to repair the wound in layers. The postoperative course was complicated by a hematoma, which developed 24 hr postoperatively. The hematoma was drained and there was no further bleeding or evidence of recurrence of the tumor after 12 months. CONCLUSION: Basal cell carcinoma should be included in the differential diagnosis of a skin lesion occurring in a port-wine stain.     

Curettage prior to Mohs'' Micrographic Surgery for Previously Biopsied Nonmelanoma Skin Cancers: What Are We Curetting? Retrospective, Prospective, and Comparative Study

BACKGROUND: Curettage prior to excision and Mohs' micrographic surgery for nonmelanoma skin cancer is performed based on the assumption that the curette will remove softer, more friable tumor-infiltrated dermis and leave structurally intact normal skin. This assumption, however, has not been objectively examined in the dermatologic surgery literature. OBJECTIVE: We performed a study to examine the ability of curettage to selectively remove and delineate nonmelanoma skin cancer prior to Mohs' micrographic surgery. METHODS: The study included 150 previously biopsied basal cell and squamous cell carcinomas less than 1.5 cm in size. We conducted (1) a retrospective study of 50 tumors curetted prior to Mohs' surgery by a surgeon who routinely curettes preoperatively; (2) a prospective study in which a surgeon who routinely does not curette preoperatively curetted 50 tumors prior to Mohs' surgery; and (3) a comparative historical group of 50 noncuretted tumors treated with Mohs' surgery by the latter surgeon. All curetted tissue was evaluated histologically. RESULTS: Only 50% of the curetted tissue demonstrated the presence of tumor in the curettings, but in 76% of these, the curette left residual tumor at the surgical margins. Of the other 50% in which the curette removed only non-cancer-containing skin, 34% had tumor present at the surgical margin. Overall, the curette removed tumor, leaving no residual tumor at the surgical margins in only 12% of lesions. Comparison with historical noncuretted tumors operated on by the same surgeon showed that curettage did not affect the mean number of stages or the proportion of tumors requiring more than one stage for histologic clearance. CONCLUSION: Although curettage may be helpful in debulking friable skin prior to Mohs' micrographic surgery, it does not reliably delineate the extent of a tumor.     

Mohs'' Micrographic Surgery of a Proliferating Trichilemmal Tumor in a Young Black Man

BACKGROUND: Proliferating trichilemmal tumor is an uncommon tumor of the follicular isthmus of the hair follicle. It usually presents as a solitary nodule on the scalp of older white women. Although these lesions typically behave in a benign fashion, recurrences and metastasis after local excision have been reported. Mohs' micrographic surgery has been effectively used to treat adnexal neoplasms. OBJECTIVE: To report a case of a proliferating trichilemmal tumor in a young black man, which was excised using Mohs' micrographic surgery. METHODS: Case report and review of the literature. RESULTS: Mohs' micrographic surgery demonstrated an irregular extension of the tumor beyond a 1 cm surgical margin. CONCLUSIONS: Proliferating trichilemmal tumors should be considered in the differential diagnosis of cutaneous neoplasms on the scalp in persons of any age (with the possible exception of infants and children), sex, or race. Mohs' micrographic surgery may be considered an optimal treatment option for proliferating trichilemmal tumors because these lesions may have an infiltrative component that may not be clinically apparent.     

Delayed reconstruction following Mohs' chemosurgery for skin cancers of the head and neck

The case records of 52 patients with 55 cutaneous neoplasms treated by Mohs' chemosurgery and subsequently reconstructed by plastic surgeons were reviewed to determine if delay between resection and reconstruction adversely affected the outcome of reconstruction. Reconstruction was performed from 5 to 61 days after Mohs' chemosurgery for 45 basal cell carcinomas and 10 other cutaneous neoplasms. There were no complications during the interval between resection and reconstruction. Following reconstruction, minor wound complications occurred in 6% of patients; there were no major complications. Microscopic examination of the re-excised wound revealed residual disease in 2 of 45 cases of basal cell carcinoma and 0 of 10 other cutaneous malignancies. Both patients with residual basal cell carcinomas (i.e., false-negative margins after Mohs' surgery) had presented to the Mohs' surgeon with recurrent tumors. During a follow-up period of 3 months to 3 years after complete resection, recurrent tumor developed in 2 of 45 cases of basal cell carcinoma and 3 of 8 cases of squamous cell carcinoma. Delayed reconstruction, usually 5 to 20 days after Mohs' chemosurgery, can be performed without significant morbidity. Re-excision of the Mohs' chemosurgical wound for pathologic examination can detect residual disease and may be especially indicated for large recurrent wounds.     

Peripheral in-continuity tissue examination: a modification of Mohs' micrographic surgery

The use of peripheral in-continuity tissue examination, in which the surgeon or dermatologist and pathologist combine their talents to remove cutaneous tumors with rapid evaluation of all margins, is useful and practical for excision of basal cell and squamous cell carcinomas that are recurrent, large, or occur in historically difficult areas to treat. This procedure, like Mohs' micrographic surgery, can be used as a tissue-sparing measure while still providing the physician and patient with confidence of complete tumor removal. Because the technique allows for primary closure and immediate reconstruction of larger and more complex tumors, patients can be spared the added inconvenience, pain, and expense of multiple separate procedures that may be necessary with Mohs' micrographic surgery or traditional tumor excision with permanent section margin evaluation.     

Mohs显微描记手术在鼻部皮肤基底细胞癌治疗中的应用

目的 评价Mohs显微描记手术治疗鼻部皮肤基底细胞癌的效果。方法 2014年,对40例鼻部皮肤基底细胞癌患者进行Mohs显微描记手术,观察手术效果,并与传统扩大切除手术进行比较。结果 40例基底细胞癌均通过Mohs显微描记法切除,肿瘤扩大切除范围平均1.8 mm。39例均Ⅰ期愈合,术后外形、效果满意。术后随访6~24个月,无1例复发。结论 对于鼻部基底细胞癌,Mohs显微描记手术比传统扩大切除更彻底,可提供更多的创面修复方案。     

High Recurrence Rates of Squamous Cell Carcinoma after Mohs'' Surgery in Patients with Chronic Lymphocytic Leukemia

BACKGROUND: Cutaneous cancers exhibit a much higher incidence in patients with chronic lymphocytic leukemia than in nonleukemic patients. Squamous and basal cell carcinomas also exhibit greater subclinical tumor extension in patients with chronic lymphocytic leukemia. OBJECTIVE: The purpose of this study was to estimate and compare the recurrence rates of squamous cell carcinoma after Mohs' surgery in patients with chronic lymphocytic leukemia compared with those in controls and to evaluate differences among squamous cell carcinoma size and histologic grade. METHODS: We retrospectively assessed the clinical histories, postoperative notes, and surgical photographs of patients with chronic lymphocytic leukemia and controls matched (2:1) for age, sex, and surgical year. Both patients and controls underwent Mohs' surgery for squamous cell carcinoma of the head and neck at the Mayo Clinic between March 1988 and April 1999. RESULTS: Twenty-eight patients who underwent Mohs' surgery for 57 squamous cell carcinomas had 7 recurrences. The cumulative incidence of recurrence on a per-tumor basis was 4.3% at 1 year, 14.8% at 3 years, and 19.0% at 5 years. Squamous cell carcinoma was seven times more likely to recur in patients with chronic lymphocytic leukemia than in controls (p = .003). The distribution of tumor histologic grade was not significantly different between patients and controls (p = .39). Maximum preoperative tumor diameters were clinically similar between patients and controls (median 15 mm vs 14 mm; p = .04). CONCLUSION: The recurrence rates of squamous cell carcinoma were significantly higher in patients with chronic lymphocytic leukemia. Squamous cell carcinomas in patients with chronic lymphocytic leukemia did not exhibit a significant difference in histologic grade or clinical difference in preoperative tumor size. Close surveillance for squamous cell carcinoma recurrence is warranted in patients with chronic lymphocytic leukemia.     

Methylene blue stain guiding layered excision in Mohs' micrographic surgery.

Resection of a continuous layer of tissue by means of Mohs' micrographic surgery is problematic at several periorbital sites. We describe a technique in which methylene blue is used to identify instances of incomplete specimen removal and thus facilitate subsequent complete removal.     

5% Imiquimod Cream and Reflectance-Mode Confocal Microscopy as Adjunct Modalities to Mohs Micrographic Surgery for Treatment of Basal Cell Carcinoma

Background. Imiquimod is an immune response modifier that up-regulates cytokines and has been shown in clinical studies to reduce or clear basal cell carcinoma tumors when applied topically.
Objective. The objectives were to evaluate the efficacy of 5% imiquimod cream in treating basal cell carcinoma preceding excision by Mohs micrographic surgery and to determine if reflectance-mode confocal microscopy is useful to establish the need for surgical intervention after imiquimod treatment.
Methods. Subjects applied study cream to one biopsy-confirmed basal cell carcinoma tumor 5 ×/week for 2, 4, or 6 weeks in this vehicle-controlled, double-blind study. Confocal microscopy was used for the 6-week treatment group to examine the target tumor area at each interval visit and immediately before Mohs micrographic surgery. After the Mohs micrographic surgery excision, the tissue was evaluated histologically, and the excision area was measured. Confocal microscopy readings were correlated to the histologic diagnosis.
Results. Tumors cleared or the target tumor area was reduced in subjects in the 4- and 6-week dosing regimens. Confocal microscopy assessments correlated well with the histologic diagnosis.
conclusion. Imiquimod improved excision results relative to vehicle when used for treating basal cell carcinoma before Mohs micrographic surgery. Confocal microscopy assessments correlated well with tumor response to therapy, suggesting that confocal microscopy may help determine the need for surgery.     

A Case of Desmoplastic Trichilemmoma of the Lip Treated with Mohs Surgery

BACKGROUND: Desmoplastic trichilemmoma is a rare pseudomalignant variant of trichilemmoma. It generally presents as a small papule on the face and is often clinically misdiagnosed as a basal cell carcinoma or verruca vulgaris. It is histologically similar to a trichilemmoma, but has a central area of desmoplasia that can mimic an invasive carcinoma. OBJECTIVE: The objective was to report a case of desmoplastic trichilemmoma of the lower lip that was treated with Mohs micrographic surgery. METHODS: A case is reported and the literature is reviewed. RESULTS: The patient underwent Mohs micrographic surgery for removal of the neoplasm. Six months after the procedure, the patient remained tumor free. CONCLUSIONS: Although desmoplastic trichilemmoma is a benign neoplasm, it is often histologically confused with basal cell carcinoma and malignant trichilemmoma. Desmoplastic trichilemmoma is also most frequently located on the face. Considering these factors, Mohs micrographic surgery appears to represent an excellent choice for removal of these tumors to achieve clear margins and a good cosmetic result.     

Mohs micrographic surgery: aplication of this technique to penile neoplasms

Mohs micrographic surgery is a surgical technique that allows the excision in successive layers of cutaneous malignancies with the higher cure rates. At the same time, this surgical technique offers the maximal preservation of normal tissue. That is possible because Mohs surgery provides the advantage of microscopically controlled tumor-free borders in each stage guiding the surgeon in the tumor persistence until the complete surgical excision. Mohs micrographic surgery is a precise treatment for penile neoplasms and its utility is justified because the removal of a substantial surgical margin of normal tissue is obviated. MoHs micrographic surgery is indicated in the treatment of penile verrucous carcinoma due to the significant risk of loco-regional recurrence after conventional surgery. Although infrequent, other penile neoplasms that can benefit from Mohs micrographic surgery are: basal cell carcinoma, extrammamary Paget's disease, in situ melanoma and granular cell tumor.     

Restylane Persistent for 23 Months Found during Mohs Micrographic Surgery: A Source of Confusion with Hyaluronic Acid Surrounding Basal Cell Carcinoma

BACKGROUND: Restylane (Q-Med, Uppsala, Sweden), a hyaluronic acid (HA) that is microbiologically produced and then cross-linked, is becoming popular as a dermal filler for improvement of facial lines and wrinkles. However, it is currently believed that the clinical and histologic persistence of this filler is from 6 to 9 months. We recently encountered Restylane in tissue where it had been implanted 23 months prior to removal of a basal cell carcinoma (BCC) on the lip, and its presence caused some confusion with HA that surrounds BCC nests. OBJECTIVE: To show and to contrast the histologic dermal appearance of Restylane and its metachromatic staining characteristics with toluidine blue from those of HA that surrounds BCC nests. METHOD: Toluidine blue staining at pH 7.07 was performed on excised tissue containing Restylane and BCC on the upper lip. RESULTS: Restylane appeared as reddish-purple amorphous masses, whereas the HA that frames BCC nests appeared redder and more well defined. Conclusion: The amorphous metachromatic reddish-purple color staining of Restylane with toluidine blue is due to its HA content. This staining pattern should be differentiated from the well-defined red color of HA that normally borders BCC nests. Restylane may persist in the dermis as long as 23 months after implantation.     

Periungual Basal Cell Carcinoma: Case Report and Literature Review

BACKGROUND Basal cell carcinoma, the most common malignancy in humans, rarely occurs on the nail unit and may be frequently misdiagnosed clinically.
OBJECTIVES To present a case of basal cell carcinoma of the nail unit successfully treated with the mohs technique and to review the literature regarding this unique presentation of this tumor.
MATERIALS AND METHODS: Case report and review of the English literature of nail unit basal cell carcinoma.
RESULTS In addition to the currently described patient, 17 other patients with nail unit basal cell carcinaoma have been reported. The tumor occurred approximately 3 times more often on the fingers then on the toes and had a slight predilection to occur in men. Ulceration, noted in more than one-half of patients, was the most common presentation of nail unit basal cell carcinoma. Mohs micrographic surgery. Often with second intention healing, was successfully employed in 39% of patients.
CONCLUSIONS Basal cell carcinaom infrequently involves the nail unit and often presents as ulceration. Adequate biopsy of the lesion is essential in making a timely diagnosis. Mohs micrographic surgery with second intension healing is an effective treatment that may offer excellent cosmetic and functional results.     

Mohs micrographic surgery for penile cancer: management and long-term followup

PURPOSE: Mohs micrographic surgery is efficacious for the primary treatment and local recurrence control of nongenital and cutaneous squamous and basal cell cancers. The efficacy of this procedure for squamous cell carcinoma of the penis was reviewed. MATERIALS AND METHODS: We retrospectively reviewed the charts of all patients treated with Mohs micrographic surgery for penile cancer at our institution from 1988 to 2006. RESULTS: We identified 33 patients who underwent a total of 41 Mohs procedures. Average +/- SD lesion size was 509 +/- 699 mm(2). An average of 2.6 +/- 1.4 stages were done using Mohs micrographic surgery. Five procedures were terminated with positive margins, including 3 due to urethral involvement and 2 due to defect size. Of the tumors 26 were stage Tis, 4 were T1, 7 were T2 and 4 were T3. A total of 13 defects were reconstructed by primary repair or granulation, 4 were reconstructed by skin grafts and 25 were reconstructed by tissue flaps and urethroplasty. Followup data were available on 25 patients at a mean of 58 +/- 63 months. Eight patients (32%) had recurrence, which was managed by repeat Mohs micrographic surgery in 7 and by penectomy in 1. There were 2 cases of tumor progression, including 1 from T1 to T3 disease (meatal involvement) and 1 from T1 to inguinal lymph node involvement. Two patients died, of whom 1 had no evidence of penile cancer and 1 had metastatic disease. CONCLUSIONS: Mohs micrographic surgery for low stage penile cancer results in a relatively high local recurrence rate. However, with repeat procedures and vigilant followup cancer specific and overall survival rates are excellent and progression rates are low.     

Current Histologic Preparation Methods for Mohs Micrographic Surgery

BACKGROUND: Recently Mohs micrographic surgery, which is widely used for the removal of nonmelanoma skin cancers, has been used to remove lentigo maligna with both rush permanent sections and frozen sections. Several investigators have incorporated the use of immunohistochemical techniques to aid in the interpretation of the specimens. OBJECTIVE: To determine the current practices of Mohs surgery laboratories, including the use of immunostains and automation of laboratory processes. METHODS: A total of 108 laboratories responded to a written questionnaire with 13 items about the types of tumors resected, routine stains performed, average number of slides processed per day, and use of automation and immunostains. RESULTS: Forty-nine percent of the laboratories are completely manual and 51% are automated. The Linistainer automated system, which is the predominant one used, decreased processing time by about 30% and provided an estimated 21-30% improved quality. Automation was associated with the number of slides processed. Immunostaining is performed by a limited number of laboratories which use the technique for basal and squamous cell carcinoma, lentigo maligna, and dermatofibrosarcoma protuberans. CONCLUSION: Automation of routine slide preparation with a Linistainer decreased staining variability by providing a consistent environment, and decreased processing time. Most laboratories do not perform immunostaining. The relatively high cost of reagents, lack of a reliable automated process, the additional time to process specimens, and the additional technician and physician time makes the procedure impractical for many laboratories.     

Economic Impact of Preoperative Curettage before Mohs Micrographic Surgery for Basal Cell Carcinoma

BACKGROUND: The role of curettage before Mohs micrographic surgery for basal cell carcinoma (BCC) remains controversial. Preoperative curettage may allow the surgeon to better delineate the subclinical extensions of high-risk BCCs, thereby enabling a more precise first-stage excision around tumor-containing tissue. OBJECTIVE: To assess the economic impact of preoperative curettage for high-risk BCCs treated with Mohs micrographic surgery on patients, providers, and insurers. METHODS: Given the enormous variability in practice styles, it was estimated that the time required to complete a second stage of Mohs surgery was 25, 50, or 75% of that required to complete the first stage. New York City Medicare and Standard reimbursement rates were used to approximate the cost of an additional stage of Mohs surgery for high-risk BCCs. RESULTS: Assuming that preoperative curettage increases operative efficiency by reducing the number of required Mohs stages from 2 to 1, the time saved can be quantified. Thus, if the Mohs surgeon estimates that the time required to remove a second stage is 75% of that of the first stage, the time savings with preoperative curettage equals 75% of the duration of a one-stage Mohs surgery. Similarly, when a second stage requires 50 or 25% of the time needed to complete the first stage, the time saved equals 50 or 25% of the duration of a one-stage Mohs surgery. Reducing the number of stages from 2 to 1 saves insurers and privately paying patients approximately $250 and $500, respectively. CONCLUSIONS: Whether preoperative curettage can offer a more precise first-stage excision without compromising tissue conservation remains a subject of debate. Preoperative curettage may reduce the number of Mohs surgical stages required for tumor clearance, potentially shortening patient encounters and allowing surgeons to treat additional patients, while decreasing costs for patients and insurers.     

δ-Aminolevulinic Acid and Blue Light Photodynamic Therapy for Treatment of Multiple Basal Cell Carcinomas in Two Patients with Nevoid Basal Cell Carcinoma Syndrome

BACKGROUND: Patients with nevoid basal cell carcinoma syndrome suffer from multiple basal cell carcinomas, requiring numerous surgical procedures that over time leave them with multiple disfiguring scars. Photodynamic therapy with delta-aminolevulinic acid using red light (approximately 630 nm) sources has been reported as effective in treatment of superficial and small nodular basal cell carcinomas. To our knowledge, the blue light source (417 nm peak irradiance) approved by the FDA for treatment of actinic keratoses has not been used for photodynamic therapy with delta-aminolevulinic acid of basal cell carcinoma. OBJECTIVE: We report treatment of two nevoid basal cell carcinoma syndrome patients, women aged 21 and 47, with 20%delta-aminolevulinic acid solution and 417-nm blue light source (irradiance 10 mW/cm(2)). METHODS: delta-Aminolevulinic acid was applied topically on lesions 1 to 5 hr before light treatment. Lesions were illuminated with 417+/-5-nm blue light for 1000 sec (10 J/cm(2)). Two consecutive treatments 1 week apart were administered as a therapeutic course. Each patient underwent two courses of photodynamic therapy with delta-aminolevulinic acid 2 to 4 months apart. The reported assessment was made 8 months after initial treatment. In most sessions the entire face, rather than visible basal cell carcinomas only, was treated. The treated basal cell carcinomas were clinically subdivided to superficial or nodular type guided by their morphologic features. A total of 9 superficial and 16 nodular basal cell carcinomas on the face and 27 superficial basal cell carcinomas on the lower extremities were treated. RESULTS: Complete clinical response was observed in 8 of 9 (89%) superficial basal cell carcinomas and 5 of 16 (31%) nodular basal cell carcinomas on the face and in 18 of 27 (67%) of superficial basal cell carcinomas on the lower extremities. The remaining 21 lesions showed partial clinical resolution. No new basal cell carcinomas were observed during the 8-month follow-up period in areas treated with a broad application technique. Resolution of the lesions was accompanied by an excellent cosmetic outcome and decreased prominence of old surgical scars in the more severely affected patient. Treatments were well tolerated, but associated with moderate to severe stinging during illumination. CONCLUSION: To our knowledge this is the first use of photodynamic therapy with delta-aminolevulinic acid with 417-nm blue light for treatment of multiple basal cell carcinomas in patients with nevoid basal cell carcinoma syndrome. Our clinical results demonstrate that the blue light reduces cutaneous tumor burden in such patients. Further studies are needed to confirm that broad-area photodynamic therapy with delta-aminolevulinic acid may eradicate subclinical tumors in nevoid basal cell carcinoma syndrome sufferers, as suggested by a strikingly decreased incidence of new basal cell carcinomas in our patients.     

Adjuvant Cytokeratin Staining in Mohs Micrographic Surgery for Basal Cell Carcinoma

BACKGROUND: Mohs micrographic surgery (MMS) is a technique that offers excellent cure rates in the treatment of basal cell carcinoma (BCC). One of the reasons for its success is the 100% visualization of the resection margins. Still, recurrences do occur in 2% to 5% of the treated BCCs. It has been suggested that BCC cells in frozen sections stained with hematoxylin and eosin (H&E) may be missed. OBJECTIVE: To determine whether an additional immunohistochemical staining with a cytokeratin marker (MNF 116) indicates BCC cells in sections in which the H&E-stained frozen sections were negative. METHODS: The Mohs procedure was performed under standard conditions in which H&E-stained slides were judged by the Mohs surgeon and the pathologist. After the H&E slides where judged negative, an extra slide was stained using immunohistochemistry and a monoclonal antibody against cytokeratin (MNF 116). RESULTS: A total of 143 complete slides were stained and judged by two Mohs surgeons and a pathologist. One of the 143 slides stained with MNF 116 showed positive staining where the H&E slides were negative, which is 0.7% of the slides. However, this single slide represents a failure of nearly 2% of the treated patients. CONCLUSION: Frozen sections stained with H&E in MMS offer enough security in detecting BCC cells during surgery; however, adjuvant cytokeratin staining can be useful in very selected cases of aggressive growing BCC.     

Value of in vivo mucosa-staining test with methylene blue in the diagnosis of pretumoral and tumoral lesions of the bladder

An in vivo staining test, methylene blue was applied to 50 patients with bladder tumor. 378 biopsies were performed in 85 areas stained with methylene blue and in 293 random biopsy areas. Of these samples, 56 had carcinoma in situ: 38 of these were not stained (68% false-negative) and the remaining 18 took up the stain. In the latter corresponding to 11 patients, carcinoma in situ was also shown in unstained areas examined by random biopsies. In 37 areas with urothelial dysplasia, 31 were not stained (84% false-negatives) while 6 cases (16%) took up the stain. Bladder tumors were stained in an irregular way but the intensity of the stain was related to the tumor grade. According to our experience the in vivo staining test with methylene blue cannot be used as a marker for pretumoral and tumoral lesions of the bladder.